The present invention relates to a water pump for motor vehicles and in particular to means for driving and journalling the shaft for the pump wheel.
In motor vehicles, water pumps are provided in association with the cooling system of the motor. The water pump comprises a pump wheel which is secured at the end of an elongated shaft journalled for rotation in a bearing and having a belt driven pulley secured to it. The bearing usually comprises a double row radial bearing provided with extensive sealing elements to prevent the entry of water or other impurities. The outer race ring of the bearing is fixed against rotation in a suitable flange extending from the motor housing. The drive pulley is usually force fit over the end of the shaft. This generally known construction has a drawback in that they comprise a plurality of individual parts which must be joined together either in manufacture or in installation. This results in an expensive, complicated construction as well as in a construction which is capable of being easily damaged. Further the known constructions require a great deal of care and attention to insure a balanced operation and a smooth rotation during installation. Since, generally built-in bearings are used which require forced installation into the supporting housing, severe difficulties are encountered in maintaining the proper tolerances in both the axial and radial spacings. As a result, bearing play is created which differs for individual bearings in each installation. Should such bearing play become too great, the revolving masses of the pump cause the parts to vibrate uncontrollably thus creating an undesirable and noticeable noise as well as creating excessive wear in critical areas and eventually the breakdown of the bearing itself.
It is the object of the present invention to provide an improved system for journalling and driving the shaft of a motor vehicle water pump which overcome the drawbacks of the known systems.
It is another object of the present invention to provide a system for journalling and driving a motor vehicle water pump which has a long operating life and is simple and inexpensive to manufacture.
It is still another object of the present invention to provide a water pump for motor vehicles which is sealed against entry of water and which provides a well balanced and smooth operation.
The foregoing objects, other objects, as well as the numerous advantages of the present invention, will be seen from the foregoing disclosure.